The present invention relates to a measurement apparatus which shares a plurality of signal terminals in a plurality of operation modes, particularly to measurement apparatuses such as a signal generator having a plurality of signal processing units corresponding to respective operation modes, a waveform analysis apparatus and a signal analysis apparatus, which share a plurality of signal terminals in respective operation modes.
FIG. 8 is an appearance view of a conventional signal generator (hereinafter referred to as a measurement apparatus as one example) for measuring performances of various apparatuses incorporated in a data communication system and a mobile communication system or a performance of a signal transmitted in a network.
That is, in this measurement apparatus, a power switch 2, an operation panel 3 in which a large number of operation buttons, operation knobs, ten keys, function keys and the like are arranged, a display 4 having a rectangular display screen 4a, a large number of signal terminals 5, and the like are attached to a front surface 1a of a housing 1 substantially having a rectangular parallelepiped shape.
Moreover, in a test apparatus regarding data transmission, a large number of measurement functions for measuring a large number of test items with one measurement apparatus shown in FIG. 8 are incorporated in the measurement apparatus.
In general, respective measurement items (functions) in the measurement apparatus are performed by individual signal processing units for the respective measurement items (functions) incorporated in the housing 1.
An operator selects/sets an operation mode for each measurement item (function) of the measurement apparatus.
For example, for the measurement apparatus for measuring the performances of various apparatuses incorporated in the mobile communication system, the respective operation modes for sending a TDMA test signal and CDMA test signal for a TDMA system, CDMA system and other communication systems employed by the mobile communication system as a measurement object are prepared in the measurement apparatus.
Moreover, in the aforementioned measurement apparatus, there is also an operation mode for measuring output signals of various apparatuses incorporated in the mobile communication system.
Additionally, types or signal numbers of the signals inputted/outputted to the outside of the measurement apparatus differ with the respective measurement items (functions) so as to perform the respective measurement items (functions) in this type of measurement apparatus.
Therefore, essentially, in this type of measurement apparatus, for each measurement item (function), it is necessary to dispose a large number of signal terminals for exclusive use in a signal processing unit for the corresponding measurement item (function) on the front surface 1a of the housing 1.
However, as shown in FIG. 8, the operation panel 3 having a predetermined occupation area is disposed on the front surface 1a of the housing 1.
The aforementioned large number of operation buttons, operation knobs, ten keys, and function keys disposed on the operation panel 3 are essential for setting test conditions in detail.
Therefore, the occupation area of the operation panel 3 in the front surface 1a cannot be reduced any more.
Consequently, in this type of measurement apparatus, for each measurement item (function), it is difficult to arrange a plurality of signal terminals for exclusive use in the corresponding measurement item (function) on the front surface 1a of the housing 1.
To solve such disadvantage, in a conventional art, a plurality of signal terminals 5a attached to the front surface 1a of the housing 1 as shown in FIG. 9A are defined as the signal terminals 5a shared for the respective measurement items (functions).
Moreover, the shared signal terminal 5a is switched and connected to the signal processing unit for performing the measurement item (function) designated in the operation mode.
However, since the type of the signal inputted/outputted to each shared signal terminal 5a attached to the front surface 1a of the housing 1 differs with each measurement item (function), a signal name cannot be put down in the vicinity of each shared signal terminal 5a attached to the front surface 1a of the housing 1.
Additionally, as shown in FIGS. 9A and 9B, individual signal name sheets 6a, 6b, . . . are prepared for the respective measurement items (functions).
Moreover, in each of the signal name sheets 6a, 6b, . . . , a through hole 7 for passing the signal terminal 5a is formed in a position corresponding to the shared signal terminal 5a, and a signal name 8 is put down in a position adjacent to each through hole 7.
Furthermore, every time the operator changes the measurement item (function) in the operation mode, the operator uses, for example, a screw, and the like to attach the signal name sheet 6a, 6b, . . . for the measurement item (function) designated in the operation mode to the front surface 1a of the housing 1 so that each shared signal terminal 5a is passed through the through hole 7.
The operator can use the signal name sheets 6a, 6b, . . . corresponding to the respective operation modes to immediately grasp the signal name of the signal to be inputted/outputted to each shared signal terminal 5a. 
However, even in the measurement apparatus in which the signal name sheets 6a, 6b, . . . shown in FIGS. 9A and 9B are used to grasp the signal names of the signals to be inputted/outputted to the respective shared signal terminals 5a, the following problems yet remain to be solved.
That is, every time the operator of the measurement apparatus changes the operation mode to start measuring a new measurement item (function), the operator needs to replace the signal name sheet 6a, 6b, . . . attached to the front surface 1a of the housing 1 with another signal name sheet 6a, 6b, . . . corresponding to the changed measurement item (function).
A replacing operation of the signal name sheet 6a, 6b, . . . is laborious. Therefore, when the measurement item (function) is frequently changed, an operation burden of the operator (measuring person) increases.
Moreover, when the number of measurement items (functions) is large, the number of signal name sheets 6a, 6b, . . . also increases. Therefore, management of the signal name sheets 6a, 6b, . . . becomes intricate.
Furthermore, every time the measurement item (function) is added, it is necessary to prepare the signal name sheet 6a, 6b, . . . for the added measurement item (function).
A measurement apparatus of the present invention is applied to a measurement apparatus in which a plurality of signal processing units for a plurality of respective operation modes concerning a signal processing are contained in a housing, and an operation panel, a display, and a plurality of signal terminals positioned in the vicinity of the display and shared by the respective signal processing units are arranged on a housing front surface.
Moreover, an object of the present invention is to provide a measurement apparatus. In the measurement apparatus, when an operator selects an operation mode, a signal name of a signal to be inputted/outputted to the shared signal terminal is automatically displayed, and operability can largely be enhanced. Even when a measurement item (function) is added, the signal name corresponding to the added measurement item (function) can easily be displayed, and the operability can further be enhanced.
To achieve the aforementioned object, according to one aspect of the present invention, there is provided a measurement apparatus comprising:
a plurality of signal processing units (16a, 16b, 16c) contained in a housing (1) and corresponding to a plurality of operation modes concerning a signal processing, respectively;
an operation panel (3), a display (4), and a plurality of signal terminals (5a) disposed in the vicinity of the display and shared by the respective signal processing units, which are arranged on a front surface of the housing;
a changeover switch circuit (17a, 17b, 17c, 18a, 18b, 18c), disposed between the plurality of signal terminals and the respective signal processing units, for switching/connecting the plurality of signal terminals to the respective signal processing units;
a signal name memory (30), disposed for each of the signal processing units, for storing a signal name of a signal allocated to the signal terminal;
switch circuit control means (22) for changing the changeover switch circuit in response to an operated/inputted operation mode designation to connect each signal terminal to the signal processing unit corresponding to the designated operation mode; and
signal name display means (25, 23) for reading each signal name corresponding to the designated operation mode from the signal name memory and displaying the signal name in the vicinity of the corresponding signal terminal in a display screen of the display in response to the operation mode designation.
In the measurement apparatus constituted as described above, the signal name of the signal allocated to each signal terminal is stored in the signal name memory for each signal processing unit corresponding to each operation mode.
Moreover, when the operator uses, for example, the operation panel to designate the operation mode, each signal name corresponding to the operation mode is read and displayed in the vicinity of each corresponding signal terminal in the display screen of the display.
Therefore, since the operator can only designate the operation mode corresponding to the measurement item (function) to confirm the signal name of the signal to be inputted/outputted to each shared signal terminal, operability of the measurement apparatus can largely be enhanced.